1. Field of the Invention
The invention relates to the field of suspension thrust bearing used, in particular, in motor vehicles on the telescopic suspension struts of the steered wheels.
The suspension thrust bearing is generally placed at the top of the suspension strut between a lower metal cup which also acts as a seat for the suspension spring, and an elastic support block. The elastic support block is made up of metallic and elastomer elements and is secured to the vehicle body. The suspension spring is arranged around the rod of a damper piston whose end, generally the end of the piston rod, is secured to the elastic support block. The suspension thrust bearing thus allows axial loads to be transmitted between the spring and the vehicle body while at the same time allowing a relative angular movement between the spring cup, which is able to rotate, and the fixed elastic support block secured to the body. This relative angular movement may be the result of a turning of the steered wheel and/or compression of the suspension spring.
It is important to make the transportation and assembly of the suspension thrust bearing with the surrounding components, and in particular with the metal cup which forms the spring seat, easier.
2. Description of the Related Art
For this, document U.S. Pat. No. 4,995,737 proposes that each of the races of the suspension thrust bearing be equipped with a plastic cap. Each cap has projections for the axial retention of the other cap, and one of the two caps has hooks capable of interacting with apertures made in the lower cup. It is thus possible to produce the suspension thrust bearing and the lower cup as a permanently-assembled entity thus making easier the operations of transporting and handling the thrust bearing/cup subassembly, the operations of mounting the subassembly in the vehicle suspension strut system and the automating of at least some of these operations.
A device of this kind does, however, have certain drawbacks:
it dictates the use of two caps made of plastic, hence increasing the cost and axial bulk of the assembly. PA1 it dictates the use of two races for the thrust bearing which, again, leads to an increase in the cost and axial bulk of the assembly. PA1 it dictates that the lower cup must have, in a precise location, an opening to interact with the hook of the lower cap, hence increasing the cost. PA1 on assembly, it is necessary angularly to orientate the lower cap of the thrust bearing relative to the opening in the cup, this making this operation and any automating thereof more complicated, thereby once again increasing the cost.
Document DE U 295 06 796 discloses a suspension thrust bearing device comprising a rolling bearing with two metal races, the lower race being in contact with a lower plastic cap which also acts as a spring seat, thus precluding the possibility of using the cup as a raceway for the rolling bodies.